SharedFileInputStream

java.lang.Object
- java.io.InputStream
- - java.io.FilterInputStream
  - - java.io.BufferedInputStream
    - - javax.mail.util.SharedFileInputStream

All Implemented Interfaces:

java.io.Closeable, java.lang.AutoCloseable, SharedInputStream
```
public class SharedFileInputStream
extends java.io.BufferedInputStream
implements SharedInputStream
```
A SharedFileInputStream is a BufferedInputStream that buffers data from the file and supports the mark and reset methods. It also supports the newStream method that allows you to create other streams that represent subsets of the file. A RandomAccessFile object is used to access the file data.
Note that when the SharedFileInputStream is closed, all streams created with the newStream method are also closed. This allows the creator of the SharedFileInputStream object to control access to the underlying file and ensure that it is closed when needed, to avoid leaking file descriptors. Note also that this behavior contradicts the requirements of SharedInputStream and may change in a future release.

Since:

JavaMail 1.4

Field Summary

Fields
Modifier and Type	Field and Description
`protected long`	`bufpos` The file offset that corresponds to the first byte in the read buffer.
`protected int`	`bufsize` The normal size of the read buffer.
`protected long`	`datalen` The amount of data in this subset of the file.
`protected java.io.RandomAccessFile`	`in` The file containing the data.
`protected long`	`start` The file offset of the start of data in this subset of the file.

Fields inherited from class java.io.BufferedInputStream
buf, count, marklimit, markpos, pos

Constructor Summary

Constructors
Constructor and Description
`SharedFileInputStream(java.io.File file)` Creates a `SharedFileInputStream` for the file.
`SharedFileInputStream(java.io.File file, int size)` Creates a `SharedFileInputStream` with the specified buffer size.
`SharedFileInputStream(java.lang.String file)` Creates a `SharedFileInputStream` for the named file
`SharedFileInputStream(java.lang.String file, int size)` Creates a `SharedFileInputStream` with the specified buffer size.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`int`	`available()` Returns the number of bytes that can be read from this input stream without blocking.
`void`	`close()` Closes this input stream and releases any system resources associated with the stream.
`protected void`	`finalize()` Force this stream to close.
`long`	`getPosition()` Return the current position in the InputStream, as an offset from the beginning of the InputStream.
`void`	`mark(int readlimit)` See the general contract of the `mark` method of `InputStream`.
`boolean`	`markSupported()` Tests if this input stream supports the `mark` and `reset` methods.
`java.io.InputStream`	`newStream(long start, long end)` Return a new InputStream representing a subset of the data from this InputStream, starting at `start` (inclusive) up to `end` (exclusive).
`int`	`read()` See the general contract of the `read` method of `InputStream`.
`int`	`read(byte[] b, int off, int len)` Reads bytes from this stream into the specified byte array, starting at the given offset.
`void`	`reset()` See the general contract of the `reset` method of `InputStream`.
`long`	`skip(long n)` See the general contract of the `skip` method of `InputStream`.

Methods inherited from class java.io.FilterInputStream
read

Methods inherited from class java.lang.Object
clone, equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - in
```
protected java.io.RandomAccessFile in
```
    The file containing the data. Shared by all related SharedFileInputStreams.
  - bufsize
```
protected int bufsize
```
    The normal size of the read buffer.
  - bufpos
```
protected long bufpos
```
    The file offset that corresponds to the first byte in the read buffer.
  - start
```
protected long start
```
    The file offset of the start of data in this subset of the file.
  - datalen
```
protected long datalen
```
    The amount of data in this subset of the file.
- Constructor Detail
  - SharedFileInputStream
```
public SharedFileInputStream(java.io.File file)
                      throws java.io.IOException
```
    Creates a SharedFileInputStream for the file.
    
    Parameters:
    
    file - the file
    
    Throws:
    
    java.io.IOException - for errors opening the file
  - SharedFileInputStream
```
public SharedFileInputStream(java.lang.String file)
                      throws java.io.IOException
```
    Creates a SharedFileInputStream for the named file
    
    Parameters:
    
    file - the file
    
    Throws:
    
    java.io.IOException - for errors opening the file
  - SharedFileInputStream
```
public SharedFileInputStream(java.io.File file,
                             int size)
                      throws java.io.IOException
```
    Creates a SharedFileInputStream with the specified buffer size.
    
    Parameters:
    
    file - the file
    
    size - the buffer size.
    
    Throws:
    
    java.io.IOException - for errors opening the file
    
    java.lang.IllegalArgumentException - if size ≤ 0.
  - SharedFileInputStream
```
public SharedFileInputStream(java.lang.String file,
                             int size)
                      throws java.io.IOException
```
    Creates a SharedFileInputStream with the specified buffer size.
    
    Parameters:
    
    file - the file
    
    size - the buffer size.
    
    Throws:
    
    java.io.IOException - for errors opening the file
    
    java.lang.IllegalArgumentException - if size ≤ 0.
- Method Detail
  - read
```
public int read()
         throws java.io.IOException
```
    See the general contract of the read method of InputStream.
    
    Overrides:
    
    read in class java.io.BufferedInputStream
    
    Returns:
    
    the next byte of data, or -1 if the end of the stream is reached.
    
    Throws:
    
    java.io.IOException - if an I/O error occurs.
  - read
```
public int read(byte[] b,
                int off,
                int len)
         throws java.io.IOException
```
    Reads bytes from this stream into the specified byte array, starting at the given offset.
    This method implements the general contract of the corresponding read method of the InputStream class.
    
    Overrides:
    
    read in class java.io.BufferedInputStream
    
    Parameters:
    
    b - destination buffer.
    
    off - offset at which to start storing bytes.
    
    len - maximum number of bytes to read.
    
    Returns:
    
    the number of bytes read, or -1 if the end of the stream has been reached.
    
    Throws:
    
    java.io.IOException - if an I/O error occurs.
  - skip
```
public long skip(long n)
          throws java.io.IOException
```
    See the general contract of the skip method of InputStream.
    
    Overrides:
    
    skip in class java.io.BufferedInputStream
    
    Parameters:
    
    n - the number of bytes to be skipped.
    
    Returns:
    
    the actual number of bytes skipped.
    
    Throws:
    
    java.io.IOException - if an I/O error occurs.
  - available
```
public int available()
              throws java.io.IOException
```
    Returns the number of bytes that can be read from this input stream without blocking.
    
    Overrides:
    
    available in class java.io.BufferedInputStream
    
    Returns:
    
    the number of bytes that can be read from this input stream without blocking.
    
    Throws:
    
    java.io.IOException - if an I/O error occurs.
  - mark
```
public void mark(int readlimit)
```
    See the general contract of the mark method of InputStream.
    
    Overrides:
    
    mark in class java.io.BufferedInputStream
    
    Parameters:
    
    readlimit - the maximum limit of bytes that can be read before the mark position becomes invalid.
    
    See Also:
    
    reset()
  - reset
```
public void reset()
           throws java.io.IOException
```
    See the general contract of the reset method of InputStream.
    If markpos is -1 (no mark has been set or the mark has been invalidated), an IOException is thrown. Otherwise, pos is set equal to markpos.
    
    Overrides:
    
    reset in class java.io.BufferedInputStream
    
    Throws:
    
    java.io.IOException - if this stream has not been marked or if the mark has been invalidated.
    
    See Also:
    
    mark(int)
  - markSupported
```
public boolean markSupported()
```
    Tests if this input stream supports the mark and reset methods. The markSupported method of SharedFileInputStream returns true.
    
    Overrides:
    
    markSupported in class java.io.BufferedInputStream
    
    Returns:
    
    a boolean indicating if this stream type supports the mark and reset methods.
    
    See Also:
    
    InputStream.mark(int), InputStream.reset()
  - close
```
public void close()
           throws java.io.IOException
```
    Closes this input stream and releases any system resources associated with the stream.
    
    Specified by:
    
    close in interface java.io.Closeable
    
    Specified by:
    
    close in interface java.lang.AutoCloseable
    
    Overrides:
    
    close in class java.io.BufferedInputStream
    
    Throws:
    
    java.io.IOException - if an I/O error occurs.
  - getPosition
```
public long getPosition()
```
    Return the current position in the InputStream, as an offset from the beginning of the InputStream.
    
    Specified by:
    
    getPosition in interface SharedInputStream
    
    Returns:
    
    the current position
  - newStream
```
public java.io.InputStream newStream(long start,
                                     long end)
```
    Return a new InputStream representing a subset of the data from this InputStream, starting at start (inclusive) up to end (exclusive). start must be non-negative. If end is -1, the new stream ends at the same place as this stream. The returned InputStream will also implement the SharedInputStream interface.
    
    Specified by:
    
    newStream in interface SharedInputStream
    
    Parameters:
    
    start - the starting position
    
    end - the ending position + 1
    
    Returns:
    
    the new stream
  - finalize
```
protected void finalize()
                 throws java.lang.Throwable
```
    Force this stream to close.
    
    Overrides:
    
    finalize in class java.lang.Object
    
    Throws:
    
    java.lang.Throwable

Class SharedFileInputStream

Field Summary

Fields inherited from class java.io.BufferedInputStream

Constructor Summary

Method Summary

Methods inherited from class java.io.FilterInputStream

Methods inherited from class java.lang.Object

Field Detail

in

bufsize

bufpos

start

datalen

Constructor Detail

SharedFileInputStream

SharedFileInputStream

SharedFileInputStream

SharedFileInputStream

Method Detail

read

read

skip

available

mark

reset

markSupported

close

getPosition

newStream

finalize